User:Hoskir/Revision Request 4238
copy only 106.3.2.59.2
106.3.2.59.2 Inertial Profiler Certification Procedures
Each IP used for construction acceptance testing on a MoDOT project shall be annually certified (verified) at a MoDOT approved certified test site in accordance with AASHTO R 56. The test site will have a known IRI in two wheel paths, measured with a reference profiler.
The MoDOT approved certification site shall issue a passing certification letter for the profiler that list the following:
- Name, Address, and Company of Profiler Operator
- Profiler ID, Manufacturer, and Model Number
- Profiler Type
- Lazer Serial Numbers
- Host Vehicle Description and VIN number
The certification letter shall list the final test results of the inertial profiler for repeatability and accuracy in accordance with AASHTO R 56 as follows:
- Minimum average cross-correlation repeatability shall be 92%.
- Minimum average cross-correlation accuracy shall be 90%.
The certification letter shall be sent to MoDOT’s Technician Certification Program Coordinator at the following email address: TechCert@modot.mo.gov.
MoDOT’s Technical Certification Program Coordinator will store a copy of the certification letter on MoDOT’s SharePoint site. The Profiler Operator shall have a copy of the certification letter available upon request.
Inertial profilers that do not pass the certification test shall be corrected offsite by their respective owners and recertified. Inertial profilers that are not certified on an annual basis shall not be used for QC or QA testing.
copy only 610.6
610.6 Areas of Localized Roughness (Sec 610.4.5.3)
Areas of localized roughness (ALR) are evaluated and addressed separately from segments. Loosely speaking, an ALR is a spot on the pavement that has a consistently high IRI using a 25 ft. rolling average. The MoDOT specification sets maximum ALR limits at either 125 (in/mi) or 175 (in/mi), depending on the operating speed and type of treatment. So an ALR exceeding 125 (in/mi) defines a point on the pavement profile that has an IRI ≥ 125 (in/mi) at any increment up to 12.5 ft. on either side. The length of the ALR depends on how far the rolling average at each adjacent increment is also ≥ 125 (in/mi).
ALRs are not measured for single-lift asphalt overlays, unless preceded by cold milling to a depth of one inch or greater.
The root causes of ALRs are variable. For new full depth pavement, they are virtually always construction-related. Construction headers, paver stops, etc are common causes. ALRs in thin overlay projects may occur through a combination of construction-related occurrences or existing geometric conditions.
All ALR locations must be identified through the ProVAL analysis. The MoDOT inspector should verify the locations by driving through the project. The engineer has the latitude to waive corrections to ALRs that are either insignificant, meaning not noticeably rough to a driver, or beyond the scope of what the project could conceivably correct. An example of the latter condition would be at an intersection on a letter route where the pavement crown is sharply thrown in and out of a superelevated profile. This would likely show up as an ALR in the ProVAL analysis. Unless the intersection had wedging corrections made prior to the overlay, the overlay by itself would not eliminate the ALR.
copy only 610.7
610.7 Dispute Resolution (Sec 610.5.5)
In the event that the QC/QA results are not within tolerance (after the absolute value of the difference between the contractor and engineer IRIs are computed for each segment within the QA test length, the average of the absolute values of the IRI difference shall be 8 in./mile or less and the absolute value of the IRI difference for any single segment shall be 12 in./mile or less), dispute resolution involving Third Party shall be conducted in accordance with Sec 403 or Sec 502. The Third Party shall test the entire disputed length with a calibrated and certified profiler. The arbitration profile shall be correlated with its corresponding QC and QA profiles in ProVAL. Whichever of the average QC/QA IRI profiles is closer to the arbitration IRI profile shall be the binding profile for the purpose of construction acceptance.